Cardiovascular function Flashcards
(43 cards)
How do you determine if it’s a vein or a artery?
Veins goes towards the heart and arteries goes away from the heart.
What are the different chambers of the heart called?
The left and right artrium and the left and right ventricle
What is the biggest arterie and vein in the heart called?
Aorta and vene cava
What does the blood consists of?
45% formed elements which is 99% red blood cells and less then one procent white blood cells and platlates. Then 55% plasma which is 90% water and around 7% plasma proteins.
What is hematocrit levels?
Percentage of red blood cells in the blood.
Where does the majority of the blood go in resting mode vs activity?
When resting most of the blood goes to the abdomnial area such as GI tract, kidneys etc. When active up to 85% of the blood goes to the working muscles.
How does the pressure gradient change throughout the cardiovascular system?
In the large arteries there is a big difference in pressure gradient and in the smaller arteries the pressure remains high but the pressure gradient becomes smaller. Most of the arterial drop occurs in the resistance bed and in the capillary bed there is no variation in pressure.
What types of arteries do we have?
Elastic arteries and muscular arteries are the two main types.
Which main categorizes can the arterial wall be divided into?
Tunica intima, tunica media and tunica adventitia
What is the arteial wall made out of?
Mostly water, but also smooth muscle, elastin and collagen, SMC and nonfibrious matrix
How is the aorta divided?
Into seven segments
What is the function of elastin and collagen in arteries?
Elastin makes the arterie able to stretch at lower pressures and collagen protects the arterie from rupturing at higher pressure levels by constricting further expansion of the artery.
What does radial strain mean?
It calculates how much the arterie can stretch from distole to sistole.
What does distensibility mean?
The radial strain given in relationship to a pressure. A high number means that the wall is elastic and a low number means that it’s not very elastic.
Whar does compliance mean?
The ability of the artery to change it’s volume in relation to pressure.
What is the windkessel effect?
It’s the wave function of the artery when it expands and contracts from the rising pressure during the systole which ends up pushing the blood forward. This saves a lot of the work for the left ventricle.
What happens with the heart as the arteries stiffen with age?
When the central arteries stiffen the work load for the left ventricle greatly increases due to the vindkessel effect diminishing.
What does measuring the pulse wave velocity inquire?
By measuring the PWV you can measure the arterial stiffness. A rigid arterie wall will lead to a higher pulse.
Which pressure parameters do we measure?
Systolic blood pressure, diastolic blood pressure, mean arterial pressure and pulse pressure. The mean arterial pressure is the average blood pressure over time.
How does the body regulate peripheral blood flow?
The easiest way is to regulate the peripheral resistance by vascilar dialation and constriction but also by blood pressure.
What is the typical flow pattern in a straight artery?
Laminar flow with an parabolic profile. This means that the blood goes in a straight line forward and the speed of the flow will be the highest in the middle of the artery and lower closer to the arterial walls.
How is the regulation of vessel diameter controlled?
By the central control from the autonomous nervous system, by certain hormones and by a local control.
How does the autonomous nervous system regulate vessel diameter?
Increased activity in sympathetic nervous endings will stimulate alpha receptors and increase the smooth muscle cells and that will decrease the luminar diameter. It also has the opposite effect on beta 2 receptors and it will also cause a release of stress hormones such as nordadrealine that also induce vessel constriction.
How does it work with local regulation of flow?
Accumulation of metabolites induce vessel dialation as well as drop in pressure which both increase blood floow proximally. Increased blood flow will stimulate releease of nitrogenoxides which causes a flow mediated dialation.
